Chipping is a term used to describe areas of concrete that have cracked and delaminated from the substrate. This deterioration of steel-reinforced concrete is characterized by the appearance of cracks and red rust, and in severe cases, the concrete sections are completely detached from the reinforcing steel bar (known as “rebar”), exposing it to the elements. There are several reasons why husking occurs, including freeze-thaw cycles, the expansive effects of the alkaline silica reaction, or exposure to fire. However, the most common cause of chipping is corrosion of embedded steel reinforcing bars or steel sections.
Corrosive steel can expand up to ten times its original volume, putting stress on the surrounding concrete. Peeling concrete is a common problem where part of the surface flakes off, breaks or splinters. Also known as flaking, it is the result of a weak surface that is susceptible to damage. Concrete shedding describes the state in which concrete begins to degrade or peel off. The threat of chipping concrete can be minimized by preparing concrete with the appropriate water-cement ratio, air content and minimum specified compressive strength, and by proper finishing.
Concrete has tremendous versatility and is used for a variety of different projects, from superstructures to pool yards. Deicing chemicals only aggravate already stressed concrete by allowing more water to migrate into concrete, increasing the size and depth of husking failures when freezing occurs.
How to Prevent Peeling ConcreteThe use of an appropriately qualified contractor is essential, as is diligent preparation of the substrate and the selection of a repair material compatible with host concrete. Common signs include cracking, crumbling or peeling of concrete, rust stains or bubbles in concrete or cement plaster, and leaks in the ceiling and walls. An additional consideration is that both delamination and descaling offer greater access of air and water to the reinforcing steel within that member; thus creating a corrosion cycle and increased access for corrosive elements that exacerbate the process with each subsequent cycle. Concrete repairs must be carried out in accordance with BS EN 1504, the European and British standard for the repair and protection of reinforced concrete.
The concrete cover is the thickness of the concrete between the outer edge of the concrete member and the steel bar, which covers or protects the steel from exposure to external elements. These cost implications are of great importance, as the effects of ignoring corrosion problems in buildings and concrete structures represent a safety risk.
The Effects of CorrosionCorrosion is known to affect all buildings and concrete structures around the world at least to some extent, and huge amounts are allocated to solve these problems. Corrosion reinforcing steel in concrete is a problem that has the ability to cause a wide range of problems ranging from economic to aesthetic. And, if you have chipping, have it treated as soon as possible to maintain the structural integrity of the concrete as much as possible.
Particular cancer can be a serious and costly problem if left untreated, misdiagnosed or given a sloppy remedy.